Field of the Invention
The present invention relates to a robot device including an arm, and more particularly, to a robot device including a replaceable end effector that is mounted to a distal end of an arm.
Description of the Related Art
In recent years, when a robot device is utilized to automatically assemble a precision component to a workpiece, in some cases, a tweezer hand for assembling a precision component and a camera for measuring the precision component are used to assemble the precision component while identifying the three-dimensional position of the precision component by the camera (see Japanese Patent Application Laid-Open No. 2011-011315).
For example, in a robot device disclosed in Japanese Patent Application Laid-Open No. 2011-011315, a stereo camera mounted to the arm is focused on the tip of the tweezer hand, and the precision component is assembled to the workpiece while controlling the position of the tweezer hand with respect to the precision component.
By the way, when the camera is mounted to the arm or the hand, it is necessary to prevent the camera from coming into contact with stands for the workpiece and the precision component, protrusions in various work spaces, or the like, which significantly restricts the motion of the arm. In particular, during a work that does not require positional control by the camera, the camera is only an obstacle for the arm, and the work efficiency may be reduced due to the restriction. Further, when the camera is mounted to the arm, it is necessary to set the specification values, such as the weight capacity, of the arm to be large, and hence the downsizing of the robot device is inhibited.
Further, in recent years, because of the intensified product competition due to the diversified customer needs, the product tends to have a shorter life cycle, and a large variety of products have been created to respond to the diversified needs. Therefore, every time the product changes, the production line and the production device need to be newly constructed or changed. Thus, there has been a problem in that it costs too much to meet large-variety production. Therefore, there has been an increasing demand not only for automatic product manufacture, but also for a robot device having high versatility, which can be used for small-lot, large-variety production.